16 Inch Kids' Gyrowheel Black Tire Model Powered-on, Gyrowheel delivers high stability at low speed. This helps the rider stay upright and learn correct riding technique quickly and easily without the nasty falls and frustration. There are three stability settings that can be reduced as skills improve and confidence grows. Comes with internal rechargable batteries and power adapter. Replaces the existing front wheel of most standard 12 inch kids' bikes. Bike not included. Recommended for ages 6-8. One year warranty. Happiness guaranteed.